This invention relates generally to alarm systems, and more specifically to ultrasonic vehicle alarm systems.
Most of the existing alarm signaling systems utilize either wire connections throughout and/or complex signal encoding techniques in connecting various intrusion detection zones to a remote alarm location. These systems are not economically adaptable to monitoring vehicles since the intrusion zone to be monitored is movable with respect to a central alarm location.
Accordingly, it is a principal object of the present invention to provide a wireless intrusion alarm system that is uni-directional enough to communicate between the vehicle and the central alarm system over a range of vehicle positions.
It is another object of the present invention to provide an intrusion alarm system that is not triggered by spurious signals and which also is resistant to jamming.
It is yet another object of the present invention to provide a vehicle alarm system that is simple, economical and which has a low power requirement permitting continuous operation.
It is another object of the present invention to provide a vehicle alarm system that has the capability of both detecting an intruder into the vehicle and vehicle movement away from a prescribed location.